1. Field of the Invention
The present invention relates to an image processing apparatus capable of correcting unevenness of exposure amounts.
2. Description of the Related Art
Conventionally, it has been known that variation in opening time and closing time of a shutter may cause unevenness in an exposure amount of an image sensor, and correcting such unevenness of the exposure amount has been requested.
As a method for correcting the unevenness of the exposure amount, for example, a technique such as discussed in Japanese Patent Application Laid-Open No. 8-154201 has been employed. According to the technique discussed in Japanese Patent Application Laid-Open No. 8-154201, a gain is calculated based on an image signal, and a gain of an image signal is adjusted according to that gain. Through this, a gain of an image captured at a different exposure amount can be precisely adjusted according to the level of the image signal. In Japanese Patent Application Laid-Open No. 8-154201, correction of two-dimensional exposure amount unevenness of the exposure on an imaging plane is not taken into consideration.